A power supply control device that controls the supply of power from a battery to a load is installed in vehicles (e.g., see JP 4473294B). In the power supply control device disclosed in JP 4473294B, a switch is connected between the positive electrode of a battery and one end of a load, and the negative electrode of the battery and the other end of the load are grounded. The power supply control device disclosed in Patent Document 1 includes a switch control portion that switches the switch on and off. The switch control portion controls the supply of power from the battery to the load by switching the switch on and off.
The switch control portion is also connected to the positive electrode of the battery, and the switch control portion receives a supply of power from the battery. At this time, current flows from the positive electrode of the battery to an output terminal via the switch control portion. The output terminal is grounded, and current that flows from the output terminal returns to the grounded negative electrode of the battery.